You seem to be missing a fundamental shift that has occurred in the U.S. and around the world over the last 30 years. You are right, the customer is king and that any companies primary goal should be to serve their customers. And in the case of Yahoo, as well as most other large American corporations that's exactly what they are doing...
What you are missing is the shift that has occurred as to who exactly the customer is. Now days, for most large corporations the customer is the stock holder. We, the consumers are the product that is being sold. With Yahoo, Google, MSN etc. it's about how many eyeballs they have looking at their pages. For companies such as Ford, GM, Target, WalMart it's all about the size of their consumer base. That's why Ford and GM don't spend a lot of time building cars that tomorrows consumers might want. Their only focus is to build as many of whatever cars the consumer is buying today.
In this new world, as far as the corporations are concerned we're just a bunch of whores and their all fighting to see who is going to be our pimp.